Change in cutaneous perfusion following 10 weeks of aerobic training in Type 2 diabetes.

A small, but positive, association between aerobic training status or prior maximal exercise and enhanced dorsal foot skin perfusion in active individuals with Type 2 diabetes has been shown. This study, therefore, was designed to examine whether an aerobic training intervention would positively affect cutaneous perfusion in sedentary Type 2 diabetic individuals as well. Nine sedentary participants with Type 2 diabetes (DS) and 10 obese nondiabetic controls (CS) were studied. Prior to the initiation of aerobic training, dorsal foot cutaneous perfusion was measured noninvasively by continuous laser Doppler assessment at baseline and during localized heating to 44 degrees C. These measurements were repeated 48-72 h following 10 weeks of moderate aerobic training performed 3 days per week. Interstitial nitric oxide (NO) levels were measured concurrently in the contralateral foot dorsum. Aerobic training did not significantly enhance baseline skin perfusion, nor were interstitial NO levels different under any condition. At baseline, groups differed only in glycated hemoglobin (HbA1c), fasting serum glucose, HDL-cholesterol, and insulin resistance. At rest, cutaneous perfusion during local heating to 44 degrees C was significantly lower in DS before training, but did not differ significantly from CS afterward. Neither group, however, experienced significant increases in dorsal foot perfusion during local responsiveness to heating to 44 degrees C following 10 weeks of moderate aerobic training, despite slightly lower perfusion in DS before training; these findings were independent of interstitial NO levels. Thus, moderate aerobic training for only 10 weeks does not appear to reverse the impairment in cutaneous perfusion of the foot dorsum in response local heating in a Type 2 diabetic population.

The effect of an aerobic exercise training program on quality of life in type 2 diabetes.

PURPOSE: The purpose of this study was to determine the effect of 10 weeks of moderate aerobic exercise training on quality of life (QOL) and selected physiological parameters in previously sedentary persons with diabetes. METHODS: A quality-of-life survey (SF36v2 health survey) and measurement of physiological parameters were completed before and after 10 weeks of supervised aerobic exercise training 3 days a week for 20 to 45 minutes by subjects with diabetes (n = 9) and control subjects (n = 10). Nontraining subjects with diabetes (n = 12) and control subjects (n = 10) also completed the QOL survey at equivalent times. RESULTS: Participants in all groups had similar characteristics. A training effect was evident in exercisers, with an increase in lactate threshold and a decrease in percent body fat for both groups. Training did not affect body mass index or interstitial nitric oxide levels. Physical and mental component scores on the QOL survey in the training and nontraining groups did not differ significantly before or after the training, and diabetes status had no significant effect on these scores. CONCLUSIONS: No physiological changes were significantly associated with scores on the SF36v2 health survey. In addition, neither training nor the presence of type 2 diabetes significantly affected the physical or mental component scores on the QOL survey.

Cutaneous blood flow in type 2 diabetic individuals after an acute bout of maximal exercise.

OBJECTIVE: We previously demonstrated a positive association between chronic aerobic exercise and dorsal foot skin blood flow during local heating in type 2 diabetic individuals. Thus, we hypothesized that a prior acute bout of maximal exercise would also have positive effects on postexercise blood flow. RESEARCH DESIGN AND METHODS: Subjects consisted of 32 individuals with type 2 diabetes and 26 nondiabetic control subjects further subdivided based on their physical activity status: diabetic exerciser (DE), diabetic sedentary (DS), control exerciser (CE), or control sedentary. Dorsal foot cutaneous blood flow was measured noninvasively by continuous laser-Doppler assessment at baseline and during local heating to 44 degrees C before and after a maximal bout of cycle exercise. Interstitial nitric oxide (NO) levels were measured concurrently in the foot dorsum. RESULTS: Increases in blood flow and its responsiveness to local heating to 44 degrees C were significantly lower in both diabetic groups compared with CE before maximal exercise, but perfusion responsiveness remained lower in DS subjects only after exercise (P < 0.05). Baseline skin blood flow was not different among groups preexercise, but it was significantly increased postexercise in DE subjects only. Interstitial NO levels were not significantly different at either time. At baseline, groups differed only in HbA(1c), fasting serum glucose, HDL cholesterol, and insulin resistance (homeostasis model assessment method). CONCLUSIONS: All diabetic individuals exhibit a blunted responsiveness of cutaneous blood flow with local heating to 44 degrees C before maximal exercise compared with active nondiabetic individuals, but after an exercise bout, it remains significantly blunted only in diabetic individuals who are sedentary. These findings occur independently of changes in interstitial NO levels.

Dental Students with Hepatitis B e Antigen: A Survey of Canadian Dental Schools.

BACKGROUD: Health care workers who are e-antigen-positive carriers of hepatitis B virus have become a significant focus of concern in the development of public health policy. In cases of needle-stick injury, the risk of transmission of HBV has been estimated at 60-fold greater if the carrier is positive for e antigen than if the carrier does not have the e antigen. Debate continues regarding proposed public health policies to restrict e-antigen-positive health care workers from performing "exposure-prone procedures". Given the potentially greater risk of disease transmission to patients and the potential career implications for infected students, dental schools must responsibly address the issue of dental students and dental school applicants who have the hepatitis B e antigen. This paper reviews the controversies surrounding this issue and reports a survey of Canadian dental schools.

Drug resistance study of Mycobacterium tuberculosis in Canada, February 1, 1993 to January 31, 1994.

OBJECTIVE: To estimate the prevalence of resistance of Mycobacterium tuberculosis to first-line antituberculosis drugs in Canada. METHODS: M. tuberculosis isolates from one third of all culture-positive tuberculosis (TB) cases diagnosed between February 1, 1993 to January 31, 1994 in Canada were collected prospectively. Proportion of drug-resistant isolates and the factors related to drug resistance were measured. RESULTS: Of 458 study cases, 40 (8.7%) had resistance to at least one first-line antituberculosis drug, of which 5.9% had mono-resistance, 0.7% had multidrug-resistance(MDR-TB)--i.e., resistance to at least isoniazid and rifampin--and 2.2% had other patterns. The overall prevalence of resistance among the foreign-born cases was 10.6% with the highest level among those who resided in Canada for less than four years (15.5%). CONCLUSIONS: Canada has a relatively low prevalence of antituberculosis drug resistance and a very low prevalence of MDR-TB. Some new immigrants to Canada may be at higher risk for drug resistance and their initial treatment needs to be tailored accordingly.

Tool use and the effect of action on the imagination.

Three studies examined the claim that hand movements can facilitate imagery for object rotations but that this facilitation depends on people's model of the situation. In Experiment 1, physically turning a block without vision reduced mental rotation times compared with imagining the same rotation without bodily movement. In Experiment 2, pulling a string from a spool facilitated participants' mental rotation of an object sitting on the spool. In Experiment 3, depending on participants' model of the spool, the exact same pulling movement facilitated or interfered with the exact same imagery transformation. Results of Experiments 2 and 3 indicate that the geometric characteristics of an action do not specify the trajectory of an imagery transformation. Instead, they point to people's ability to model the tools that mediate between motor activity and its environmental consequences and to transfer tool knowledge to a new situation.

Onset and duration of action of levocabastine nasal spray in atopic patients under nasal challenge conditions.

BACKGROUND: Although prior studies have documented the rapid onset of action of topical intranasal levocabastine (LEV), little is known about its duration of action under nasal challenge conditions. OBJECTIVES: We sought to assess the onset and duration of action of escalating doses of LEV nasal spray by using a nasal allergen challenge (NAC) model. METHODS: Eighteen asymptomatic subjects with histories of seasonal allergic rhinitis were enrolled into a randomized, single-blind, placebo-controlled, dose-ranging crossover study. Each patient was randomly assigned to receive single doses of placebo and intranasal LEV 0.1, 0.2, and 0.4 mg during 2 parts of the study. In part 1 (onset of action), NAC consisted of a single dose of allergen administered 5 minutes after study drug treatment. In part 2 (duration of action), NAC consisted of increasing doses of allergen administered 0.5, 6, 12, and 24 hours on separate days after study drug treatment. Nasal symptom scores (NSSs) and nasal peak expiratory flow rates were measured after NAC in both phases of the study. Blood samples for plasma LEV concentrations were drawn after each NAC. RESULTS: In part 1, NSSs were significantly lower after the administration of LEV 0.1, 0.2, and 0.4 mg compared with placebo (P <.05). In part 2, NSSs were significantly lower after LEV doses of 0.2 and 0.4 mg compared with placebo at 0.5, 6, 12, and 24 hours after treatment (P <.05). The mean provocative dose of allergen required to elicit a positive nasal reaction was increased after LEV doses of 0.2 and 0.4 mg at 0.5, 6, and 12 hours after treatment. Nasal peak expiratory flow rates demonstrated no significant differences between LEV and placebo for any doses at any time points. Mean plasma LEV concentrations were low (range, 0 to 3. 7 ng/mL) after all doses and did not correlate with drug efficacy. CONCLUSIONS: Single intranasal LEV doses of 0.1, 0.2, and 0.4 mg significantly reduced the severity of the immediate nasal response to allergen when administered 5 minutes before NAC. This protective effect against NAC continued to be present 24 hours after administration of LEV doses of 0.2 and 0.4 mg. Efficacy in blocking the reaction to NAC did not correlate with plasma LEV levels, suggesting that the inhibitory effect was due largely to topical rather than systemic effects.

Efficacy and safety of levocabastine nasal spray for seasonal allergic rhinitis.

This multicenter, double-blind, placebo-controlled trial evaluated the efficacy and safety of levocabastine nasal spray, a potent and selective H1-receptor antagonist, in the control of histamine-mediated symptoms of seasonal allergic rhinitis. Adults with > or = 2 year history of allergic rhinitis due to Mountain Cedar were randomized to treatment with levocabastine nasal spray (0.2 mg twice daily) or placebo for 28 days during the 1994-1995 Mountain Cedar allergy season. Patients assessed the severity of their rhinitis symptoms on a four-point scale twice daily. At the end of the trial, patients also performed a global evaluation of treatment efficacy on a five-point scale. Overall for the 4-week treatment period, levocabastine nasal spray significantly reduced major nasal (runny nose and sneezing) and primary rhinitis (runny nose, sneezing, and itchy/gritty eyes) symptoms compared with placebo on both repeated measures (p = 0.023; p = 0.01) and ANOVA (p = 0.003; p < 0.001) analyses. Global evaluations of treatment efficacy at the end of the trial significantly favored levocabastine over placebo (p = 0.002). Overall, the incidence of adverse events was similar for both treatment groups. In general, most adverse events were mild in intensity, with sinusitis (17% each group), headache (17% placebo, 14% levocabastine), and rhinitis (8% placebo, 2% levocabastine) most commonly reported. Levocabastine nasal spray 0.2 mg twice daily was significantly more effective than placebo in the relief of histamine-mediated symptoms in patients with seasonal allergic rhinitis and was well tolerated over the 28-day treatment period.

A Canadian multicentre case-control study of sporadic Escherichia coli 0157:H7 infection.

OBJECTIVE: To evaluate further risk factors for Escherichia coli 0157:H7 infection including consumer preferences related to the consumption of ground beef and the role of person-to-person transmission of this infection. PATIENTS AND METHODS: A case-control study of sporadic E coli 0157:H7 infection was undertaken in five Canadian cites from June to December 1991. One hundred cases of E coli 0157:H7 infection were age- and sex-matched to 200 neighbourhood controls. Cases and controls were interviewed face-to-face to obtain information on potential risk factors for infection and health outcomes. Daycare providers of case and control children were interviewed regarding risk factors for infection at the institutional level. Contacts of cases and controls who reported diarrhea in the seven days before the case onset date were also interviewed about their symptoms and risk factors. RESULTS: All cases had diarrhea during the course of their illness and 90 (90%) reported bloody diarrhea. Four (4%) were reported to have developed hemolytic uremic syndrome; however, there were no fatalities. Sixty-one (61%) of patients were hospitalized. Two variables were associated with infection in the final conditional logistic regression model: eating pink hamburger patties (odds ratio = 12.4, P=0.0001, population attributable fraction =40.2%) and contact with a nonhousehold member suffering from diarrhea (odds ratio = 7.0, P=0.0054, population attributable fraction = 10.3%) in the seven days before illness. Forty per cent of cases and controls who indicated that they prefer well done hamburgers said they would eat a 'pink' hamburger if served to them rather than ask that the hamburger be cooked longer. CONCLUSIONS: Health care workers should remain vigilant in their efforts to educate the public as to the risks associated with the consumption of ground beef that is inadequately cooked, and the importance of personal hygiene in the prevention of enteric illness.

Increased glucocorticoid activity in men with cardiovascular risk factors.

The association between hypertension and insulin resistance might be explained by increased activity of the principal glucocorticoid, cortisol. Recent data show that the intensity of dermal vasoconstriction after topical application of glucocorticoids is increased in patients with essential hypertension. In this report, we examine whether increased glucocorticoid sensitivity or secretion is associated with insulin resistance and is a cause or consequence of hypertension. We studied 32 men (aged 47 to 56 years) from a cross-sectional study and 105 men (aged 23 to 33 years) in whom predisposition to high blood pressure has been defined by their own blood pressure and the blood pressures of their parents. In both populations, increased dermal glucocorticoid sensitivity was associated with relative hypertension, insulin resistance, and hyperglycemia. In young men with higher blood pressure whose parents also had high blood pressure, enhanced glucocorticoid sensitivity was accompanied by enhanced secretion of cortisol, enhanced ligand-binding affinities for dexamethasone in leukocytes, and impaired conversion of cortisol to inactive metabolites (cortisone and 5beta-dihydrocortisol). Increased tissue sensitivity to cortisol, amplified by enhanced secretion of cortisol, is a feature of the familial predisposition to high blood pressure rather than a secondary effect of high blood pressure. It may be mediated by an abnormal glucocorticoid receptor, and it may contribute to the association between hypertension and insulin resistance.

Impaired microvascular dilatation and capillary rarefaction in young adults with a predisposition to high blood pressure.

Increased vascular resistance in essential hypertension occurs mainly in microvessels with luminal diameters < 100 microm. It is not known whether abnormalities in these vessels are a cause or consequence of high blood pressure (BP). We studied 105 men (aged 23-33 yr) in whom predisposition to high blood pressure has been characterized by both their own BP and those of their parents. Factors that are secondary to high BP correlate with offspring BP irrespective of parental BP, but factors that are components of the familial predisposition to high BP are more closely associated with higher BP in offspring whose parents also have high BP. Offspring with high BP whose parents also have high BP had impaired dermal vasodilatation in the forearm following ischemia and heating (289+/-27 [n = 25] versus 529+/-40 [n = 26], 476+/-38 [n = 30], and 539+/-41 flux units [n = 24] in other groups; P < 0.0001) and fewer capillaries on the dorsum of the finger (23+/-0.8 capillaries/0.25 mm2 versus 26+/-0.8 in all other groups; P < 0.003). Except for BP, other hemodynamic indices (including cardiac output and forearm vascular resistance) were not different. The dermal vessels of men who express a familial predisposition to high BP exhibit increased minimum resistance and capillary rarefaction. Defective angiogenesis may be an etiological component in the inheritance of high BP.

Status of tuberculosis infection control programs in Canadian acute care hospitals, 1989 to 1993 - Part 1.

OBJECTIVE: To document tuberculosis (TB) prevention and control activities in Canadian acute care hospitals from 1989 to 1993. DESIGN: Retrospective questionnaire. PARTICIPANTS: All members of the Community and Hospital Infection Control Association-Canada and l'Association des professionnels pour la prévention des infections who lived in Canada and worked in an acute care hospital received a questionnaire. One questionnaire per hospital was completed. OUTCOME: The study documented the number of respiratory TB cases admitted to the hospital, the type of engineering and environmental controls available, and the type of occupational tuberculin skin test (TST) screening programs offered by the hospital. RESULTS: Questionnaires were received from 319 hospitals. Ninety-nine (32%) hospitals did not admit a respiratory TB case during the study. Thirty-one (10%) hospitals averaged six or more TB cases per year. TST results were reported for 47,181 health care workers, and 819 (1.7%) were reported as TST converters; physicians had a significantly higher TST conversion rate than other occupational groups. Most hospitals did not have isolation rooms with air exhausted outside the building, negative air pressure and six or more air changes per hour. Surgical masks were used as respiratory protection by 74% of staff. CONCLUSIONS: Canadian hospitals can expect to admit TB patients. Participating hospitals did not meet TB engineering or environmental recommendations published in 1990 and 1991. In addition, occupational TB screening programs in 1989 to 1993 did not meet Canadian recommendations published in 1988.

Comparison of tuberculosis infection control programs in Canadian hospitals categorized by size and risk of exposure to tuberculosis patients, 1989 to 1993 - Part 2.

OBJECTIVE: To analyze tuberculosis (TB) programs in acute care hospitals (hospitals) categorized by size and risk of exposure to TB patients from 1989 to 1993. DESIGN: Retrospective survey. PARTICIPANTS: Members of the Community and Hospital Infection Control Association-Canada and l'Association des professionnels pour la prévention des infections who worked in Canadian hospitals received questionnaires. One questionnaire per hospital was completed. OUTCOME: Hospitals reported the number of respiratory TB and human immunodeficiency virus (HIV) cases admitted, the engineering and environmental controls available, and the type of occupational TB screening programs available. Data were stratified by hospital size and risk of exposure to TB patients. RESULTS: Thirty-four (10.9%) hospitals with at least 500 beds admitted more than 50% of the TB cases, more than 40% of the multidrug-resistant TB (MDR-TB) cases and more than 65% of the HIV cases. Thirty-six (11.6%) facilities classified as high risk hospitals reported more than 70% of the TB cases, more than 58% of the MDR-TB cases and more than 75% of the HIV cases. A significantly higher pooled average tuberculin test conversion rate was found in individuals working in high risk (4.4%) than in low risk hospitals (1.5%). Significantly more high risk than low risk hospitals had an isolation room with air exhausted outside, negative air pressure and at least six air changes per hour. Only 13 high risk hospitals had all three engineering characteristics. Surgical masks were used for respiratory protection in 18 (50%) high risk and 186 (77.8%) low risk hospitals. CONCLUSIONS: Nosocomial transmission of Mycobacterium tuberculosis may have occurred because TB programs available in many Canadian hospitals were inadequate.

Rapid progression to disease in African sex workers with human immunodeficiency virus type 1 infection.

From a cohort of female sex workers in Nairobi, Kenya, 163 women were observed to seroconvert to human immunodeficiency virus type 1 (HIV-1) and followed to study progression to HIV-1-related disease. The effect of several covariables on disease progression was studied using a Weibull proportional hazards model. The Weibull survival model was fitted to the observed incubation times. Estimates of the median duration to CDC stage IV-A and IV-C disease were 3.5 and 4.4 years, respectively. Condom use before seroconversion was associated with a reduced risk of CDC stage IV-A disease (relative risk = .64, P < .05). The incubation time of HIV-1-related disease is extremely short in this population.

An outbreak of diarrhea due to verotoxin-producing Escherichia coli in the Canadian Northwest Territories.

In the summer of 1991 a large outbreak of Escherichia coli O157:H7 associated diarrhea occurred in 6 Inuit communities in the Canadian Northwest Territories. The total population of these communities is 5,292. Of the 521 individuals who developed diarrhea, 152 (29%) were positive for E. coli O157:H7 on stool culture or positive by verotoxin analysis. Median age was 6 years. The attack rate for children < 1 year was 43% in the major affected community of Arviat. Hemolytic-uremic syndrome (HUS) developed in 22 cases, and 2 patients died. Asymptomatic stool carriage of verotoxin-producing E. coli (VTEC) 2-5 weeks after diarrheal illness was noted in 4/28 persons followed prospectively. Epidemic curves, case-control studies and phage type testing suggested person-to-person transmission. The original source of infection was not identified, though a food source was suspected. VTEC were detected in 6 food samples (minced beef and caribou) taken from retail outlets and homes. Primary prevention of infection through health education and promotion activities, as well as long-term follow-up of HUS survivors, are indicated in this population.

Morbidity, cost and role of health care worker transmission in an influenza outbreak in a tertiary care hospital.

An influenza A outbreak involving 17 health care workers (HCWs) and 16 chronic geriatric patients on a ward in a tertiary care hospital was reviewed. Thirty-seven per cent of all HCWs and 47% of patients on the affected wards became ill with influenza. Three patients died during the outbreak. The majority of health care workers became ill prior to detecting the first patient case of influenza, suggesting that nosocomial spread from HCWs to patients may have occurred. Only 13.7% of the staff and 5.9% of the patients had been vaccinated prior to the outbreak. Lost time due to HCW absenteeism, outbreak-related medication costs and additional staff time involved in outbreak control resulted in considerable cost to the hospital. It is suggested that much of this cost, as well as morbidity and possibly mortality, could have been avoided by increased immunization of HCWs and patients.